1. Field of the Invention
The present invention relates to a digital camera with a collapsible lens barrel.
2. Description of Related Art
Recently, in addition to the promotion of pixel quantity and zoom ratio, digital cameras have become even thinner than before. An effective means to minimize the thickness of the digital camera is to reduce clearances between lens sets and a picture pick-up device when the digital camera is switched off. Thus, the digital camera is generally provided with a telescopic lens frame which can extend out and retract into a camera body.
In the prior art, a non-patent document (titled “Digital CAPA”, page 20-22, No. 3, Vol. 19, Mar. 1, 2003, published by Study & Research Institute, Japan,) discloses a digital camera with a collapsible lens barrel. The method for minimizing the thickness of the digital camera is to move the second lens set beside the picture pick-up device while the lens barrel is retracted.
However, the performance of the digital camera not only depends on the pixels of image sensor and the zoom ratio, but also depends on the performance of the optical system. For the optical system of general digital cameras, the alignment of the first and second lens sets is greatly related to the optical performance. The method disclosed in the non-patent document will cause the optical axis of the second lens set tilt or misalignment, when the second lens set is moved beside the image sensor. Therefore, the prior art still has some problem, which can not be solved.
Therefore, the invention provides a compact digital camera and obviates the aforementioned problems.